How to Set BDC Model LobSystemInstance Proerties in Sharepoint 2010

I got a little bit frustrated when i try to follow an MSDN article Creating .NET Assemblies That Aggregate Data from Multiple External Systems for Business Connectivity Services in SharePoint Server 2010 to store the database connection in the BDC Model.

here is the steps to following for properly setup the 

1. open the BDC Explorer. Select the LobSystemInstance property, 
2.  and then in the Properties pane, click Custom Properties. 
3.  In the Property Editor dialog box, click on the Add Button to enable a row.
4.  You must enter the value that are associated with the property first before you enter the name of the property. I scratch my head hard to figure out this. if you enter the property name, then the value. you will see only the Cancel and delete buttons are enable. after you complete the properties name, then hit enter key, the OK now is enable. you can click OK to set the property.